Bounds checking in extension API

[Simon Glover]

What, if any, validation of their input should the register access
functions in the extension API do? Currently, they don't do any,
which means that you can create a buffer overflow simply by using
a register number >31 or <0; eg,

Parrot_set_intreg(interpreter, 100000000, 100);

reliably segfaults on my machine. Is it the responsibility of the
extension writer to do this kind of bounds checking (in which case
we need to make this extremely plain in the documentation), or should
Parrot do this itself?

Simon

[Dan Sugalski]

This ought to be done by the extension API, though it was something I
skimped on when I was throwing it together.

Dan

[Simon Glover]

OK, so what do we do in response to an out-of-bounds access? Throw a
Parrot exception? Or indicate an error in some other fashion?

Simon

[Dan Sugalski]

Throw an exception. Which, I see, there isn't a facility to do from an
extension. We need to fix that...

Dan